Well drilling mud and the method of making the same



V t I 2,9 4,019 WELL DRm nIG MUD 'AND 'rrmivrs'rnon'or ZMAKINGTHE SAME j James'V. Thompson, Denver, Colo., assignor to James V. Thompson and Alfred G. Hoyl, a. partnership The present invention relates to the oil and gas well containing the new mud to direct and alternating electrical fieldsto increase anddecrease respectively the viscosity and flocculationcharacteristics.of thefluid;

drilling art and more specifically to mud-laden fluids V used in the drilling of oil and gas wells.

Heretofore, mud-laden fluids have been utilized in gas and oil well drilling operations for the purpose of performing a number of desired functions and obtaining certain desired and advantageous results. Principally these functions obtained by the use of mud-laden fluids are as follows: V

(a) To lubricate and cool drill stems and drill bits in the bore holes; t

(b) To pickup cuttings produced by the drill bit andiconduct them to the surface through the bore hole;

(c) To plaster or form a thin filter cake or coating on the walls of the bore hole to reduce water loss and softening of the bore hole walls; and

(d) To furnish a hydrostatic head-pressure in the bore hole preventing flow into the hole of formationfluid from the various strata aspenetrated bythe drill bit. t I I. The. advantages of the present invention as they relate to the above enumerated functions of gas and oil well mud will become more readily, apparent hereinafter as.

they are specificallyset forth in thefollowing disclosures.

It is a principal object of the present'invention to pro videa new and improved mud composition for use in oil and as wells which is obtained through, the practice of ing in. a common'millof prescribed quantities; of raw,

a new and unique method of manufacture of fthe mud from aplurality ofimineral ingredients. I

Another objecttof this 'nvention is theprovisionofa v new an 'd improved mud composition for use in .oil. and gas wells which consists .of a homogeneous mixture .of

quantifies of magnetite and micaceous material which mixture is dispersible or suspensible in a fluid vehicle to form a mud-laden fluid.

. A further object of this invention is the provision of anewfland' improved mud for oil and gas wells which has the specific advantages of: non-abrasive characteristic;

increased shear strength; increased filtering qualities; and

greater stability against separation ofingredients.

Still anotherobject of this invention is the provision.

of a new and improved mud of thetype described which, by reason of'its increased shear strength, serves more efliciently to pickup and conduct cuttings vertically througlilthe bore hole and-to maintain such cuttings in elevatedip'ositionswithin the .hole when rotation of the drill is stopped during PGIiOIdSgOf temporary shutdown.

Anothenand further advantageof this invention is H the provision of a mud composition of the type herein-' before described which has an inherentlyimproved filter- 1 ing characteristic whichdresults in the thin formation of a"wall fi.co"atf or plaster within the bore {hole'which in creasesthe reductionofwat er loss and serves to maintain head pressure within the bore hole more effectively and efficiently than has been heretofore attained. V

Still a further object of this invention is the provision of a new and improved drilling mud of the type hereinbefore described which, by reason of its homogeneous :non-separating characteradapts it to a new and unique niiculite.

Table I 1 By By Mud Composition. Weight, Volume, V 1 Percent lercent vermiculite (expandedL Q i I 7.1 25' Man-netita 1 92.9

Table II --.-B -;i. fig-E Mud Composition Weight, Volume, Percent Percent Vermiculite(unexpanded). ic 7 11.6 40.28 Magnptitc 88 4 59. 72

i v It has been discovered that practice of the above method '8 ill another and important object of this inventionis the provision of a new andimproved method for coinpounding a mud for suspension in an oil and gas well sealing fluid which consists in the simultaneous grinding of raw, bulkmagnetic and micaceous material to produce a composition of finely divided particles composed of micaceous material uniformly impregnated with magnetite which is suspensible or dispersible in an aqueous vehicle.

Yet another object of this invention residesv in the provision of a new and improved "method of manufacture and of the unique compositions.hereinbeforeset forth which enables the provision of a muclfor use in oil and gas wells having the highly improved characteristics and advantages heretofore set forth which may be made available to the industry at costs comparable with costs of muds currently utilized. 7 Still other objects and advantages of this invention will become more readily apparent to those skilled in the art when the following description and examples are considered.

The composition of the present invention may be briefly described as a homogeneous mixture of finely divided magnetite and micaceous such as vermiculite, .wherein the magnetite particles are uniformly impregnated in the micaceous material particles. This homogeneous mixture is capable of being dispersed or suspended in an aqueous vehicle which then forms a mud or solid-laden liquid for use in gas or oil well bore holes. g

The method of the present invention may be described briefly aslthe manufacture or'compounding of a mud com: position for use in suspensiongin a fluid for oil and gas well boreholes which consistsinthesimultaneous grind bulkrmagnetite and a micaceous material to reduceithe bulk mixture to a substantially uniform particle sizc, of

1-325 mesh or less and to homogeneously admix the parf ticlesi of 'the two ingredients to embed the magnetite-particles uniformly in the vermiculite particles.

By way-of specific examples of the method of the presmagnetitep'articles are uniformly embedded in the verie s ed, w 19 7 utilizing quantities of vermiculite, by weight, varying from to 50% will produce a drilling mud composition attaining the numerous advantages hereinbefore set forth. It has been, discovered that as the percentage of vermiculite ground with the magnetite increasesthe viscosity ofthe resultant drilling fluid'in which the composition is suspended increases with an accompanying increasein the gel strength of the fluid. [Increase in the fluidgel strength serves to increase the filtration characteristic as well as theshear strength .characteristics of the fluid to obtain the advantageshereinbeforefattributed to these factors.

As an additional facet of my discovery, I have found that by physically embedding the magnetite, which has heretofore been utilized in drilling fluids .as a weighting agent, in the vermiculite, which has heretofore been used as a'suspending agent to produce a non-separating homogeneous mixture of these elements that a ready and positive control of the viscosity of the drilling fluid in which the mud composition is suspended may be attained. For example, by passing the drilling fluid through a tube or pipe having an electrical coil wound therea'hout enables the subjecting of the fluid selectively to a direct or an alternating current field. When the drilling fluid is subjected to a direct current field the magnetite particles Within the fluid become magnetized producing an adherence among such particles within .the fluid forming a flock. Such magnetically flocculated fluid has a characteristically high viscosity. Alternately, by subjecting the drilling fluid to an alternating current field the magnetite particles are demagnetized thereby destroying magnetic flocks and thereby characteristically reducing the viscosity of the fluid.

It has been further discovered that the viscosity of the fluid .is controllable over a wide range by varying the relative intensity of the magnetic field of the coil through which the drilling fluid is passed. 7

An additional advantage, knowledge of which has arisenthroug'h use of the new and improved mud hereinbefore described, rests in the ability of this new mud composition to be cleaned at the wellhead location by the utilizationof commercial magnetic separators. The magnetic qualities of the presentjmud enable the cleaning of spirit and scope of my discoveries and'invention.

Having thus described and fully disclosed and expalined my present invention and the highly desirable objects and advantages obtained through the practice thereof, what I desire to claim is:

1. A composition for use as a weighting agent in a illi g fluid f r il an g s e s. co pr n a on-s p rating homogeneous mixture of fine particles of vermiculite impregnated with fine particles of magnetite, the proportion of vermiculite to magnetite by weight being bet-ween 5 and 5.0 percent.

.2- .A co rpc itio as fin d i c a m 1 herei t vermiculite is expanded.

3. A composition as defined in claim 1 wherein, the vermiculite is unexpanded.

4. A composition as defined in claim 1 wherein, the vermiculite is expanded and by weight the proportion of vermiculite to magnetite is 7.1 percent.

5. A composition as defined in claim 1 wherein the vermiculite is unexpanded and by weight the proportion of vermiculite to magnetite is 11.6 percent 6. The method of producin a composition for use as a weighting agent for a drilling fluid for oil and gas wells consisting of simultaneously grinding a mixture of bull; magnetite and bulk vermiculite to a reduced particle size, the proportion of vermiculite to magnetite by weight in said mixture being between 5 and 50 percent.

7. The method of producing a composition for use as a weighting agent fora drilling fluid for oil and gas wells consisting of simultaneously grinding a mixture of bulk magnetite and bulk vermiculite to a particle size of 325 mesh and less, the proportion of vermiculite to magnetite by weight in said mixture being between 5 and 50 percent.

8. The method of producing a composition for use as a weighting agent for a drilling fluid for oil and gas wells comprising, simultaneously grinding to a fine particle size a mixture of "bulk .magnetiteand bulk vermiculite wherethe mud through magnetic separation down to very fine sizes as opposed to the herebefore normal practice .of cleaning'prior muds by screening with extreme limitations on the fineness'of the cleaning separation. These prior screening operations have been attended by a ,high loss of mud gravity which -has necessitated the building upof the remaining mud after cleaning with expensive materials-such as barite to 'bring the mud gravity back to its minimum limits. Such additives are not required in the present mud since the magnetic separation will not afiect'the'mud gravity due to the high efficiencyrof cleaning by such method.

The foregoing disclosures make readily evident that a new and 'highly improved mud composition for aqueous suspension in the formation of a mud-laden drilling fluid has been provided which attains objects and advantages heretofore unobtainable and unknown in the art. Additionally, the utilization of a mud composition of the type herein .described and compounded by the new and improved m thod herein disclosed enables the accomplishment of not only new but substantially unexpected results which serve to increase the efficiency and the adaptability of mud-laden liquid in the gas andoil :well drilling .art.

Obviously many variationsand combinations are possible Within the .rangesof ingredient proportion to satisfyrequired: mud characteristics dependent upon individual in the proportions of vermiculite to magnetite by weight is between 5 and '50 percent to cause the ,vermiculite'to be impregnated with magnetite by having magnetite embedded therein.

'9. The method defined in claim 8 wherei the bulk magnetite and bulk vermiculite are ground to a substantially uniform particle size of 325 mesh or less and the grinding is continued until the magnetite particles are uniformly. embedded in the vermiculite particles.

10. A method of controlling the viscosity of .a mudladen fluid for use in drilling oil and gas Wells containing finely ground particles of vermiculite impregnated with magnetite, said vermiculite being .in proportion to the magnetite. in the order of from 5 to 50 percent by weight,

including the steps of subjecting the fluid to a direct current magnetic field to produce flocculation of theifluid, and ec ng the u d a lt r a ins u rsn ma neti field to deflocculate the fluid.

RefierehicesGited in the file of this patent U I D STATES PATENTS 2,122,236 Nicholsetal megs, .1938

2.2161075 Wuensch :Mar. '10, 1942 1,2 3,564 :Means :May 19,1942

,roRE N PATENTS c r-HER REFERENCES New Us s .fc Ma net Fluids, ar c i Bu a anda d Bulletin June 1949, case 1. 75. 16 5- 

1. A COMPOSITION FOR USE AS A WEIGHTING AGENT IN A DRILLING FLUID FOR OIL AND GAS WELLS, COMPRISING A NON-SEPARATING HOMOGENEOUS MIXTURE OF FINE PARTICLES OF VERMICULITE IMPREGNATED WITH FINE PARTICLES OF MAGNETITE, THE PROPORTION OF VERMICULITE OF MAGNETITE BY WEIGHT BEING BETWEEN 5 AND 50 PERCENT.
 10. A METHOD OF CONTROLLING THE VISCOSITY OF A MUDLADEN FLUID FOR USE IN DRILLING OIL AND GAS WELLS CONTAINING FINELY GROUND PARTICLES OF VERMICULITE IMPREGNATED WITH MAGNETITE, SAID VERMICULITE BEING IN PROPORTION TO THE MAGNETITE IN THE ORDER OF FROM 5 TO 50 PERCENT BY WEIGHT INCLUDING THE STEPS OF SUBJECTNG THE FLUID TO A DIRECT CURRENT MAGNETIC FIELD TO PRODUCE FLOCCULATION OF THE FLUID, AND SUBJECT THE FLUID TO AN ALTERNATING CURRENT MAGNETIC FIELD TO DEFLOCCULATE THE FLUID. 